The Musculoskeletal Infection Society (MSIS) criteria,3, 4 one of the most globally accepted PJI diagnostic strategies, selects aspiration culture and the presence of the sinus tract as the major criteria and chooses other routine serum and synovial tests like serum C‐reactive protein (CRP), erythrocyte sedimentation rate (ESR), synovial white blood cell (WBC), and synovial polymorphonuclear neutrophils (PMN%) as minor criteria, similar to the diagnostic criteria published by the Infectious Diseases Society of America5 and the European Bone and Joint Infection Society criteria.6 This evidence concerns the gene CRP and infection.